Add criteria based IndexWriter changes behind a setting

server/src/main/java/org/opensearch/cluster/metadata/IndexMetadata.java

@@ -342,6 +342,7 @@ public Iterator<Setting<?>> settings() {
     );
 
     public static final String SETTING_REMOTE_STORE_ENABLED = "index.remote_store.enabled";
+    public static final String SETTING_CONTEXT_AWARE_ENABLED = "index.context_aware.enabled";
 
     public static final String SETTING_REMOTE_SEGMENT_STORE_REPOSITORY = "index.remote_store.segment.repository";
 
@@ -384,6 +385,13 @@ public Iterator<Setting<?>> settings() {
         Property.Dynamic
     );
 
+    public static final Setting<Boolean> INDEX_CONTEXT_AWARE_ENABLED_SETTING = Setting.boolSetting(
+        SETTING_CONTEXT_AWARE_ENABLED,
+        false,
+        Property.IndexScope,
+        Property.Dynamic
+    );
+
     /**
      * Used to specify remote store repository to use for this index.
      */

server/src/main/java/org/opensearch/common/settings/IndexScopedSettings.java

@@ -256,6 +256,8 @@ public final class IndexScopedSettings extends AbstractScopedSettings {
                 IndexSettings.INDEX_CONTEXT_CREATED_VERSION,
                 IndexSettings.INDEX_CONTEXT_CURRENT_VERSION,
 
+                IndexMetadata.INDEX_CONTEXT_AWARE_ENABLED_SETTING,
+
                 // validate that built-in similarities don't get redefined
                 Setting.groupSetting("index.similarity.", (s) -> {
                     Map<String, Settings> groups = s.getAsGroups();

server/src/main/java/org/opensearch/index/IndexSettings.java

@@ -790,6 +790,7 @@ public static IndexMergePolicy fromString(String text) {
     private final int numberOfShards;
     private final ReplicationType replicationType;
     private volatile boolean isRemoteStoreEnabled;
+    private volatile boolean isContextAwareEnabled;
     private final boolean isStoreLocalityPartial;
     private volatile TimeValue remoteTranslogUploadBufferInterval;
     private volatile String remoteStoreTranslogRepository;
@@ -994,6 +995,7 @@ public IndexSettings(final IndexMetadata indexMetadata, final Settings nodeSetti
         numberOfShards = settings.getAsInt(IndexMetadata.SETTING_NUMBER_OF_SHARDS, null);
         replicationType = IndexMetadata.INDEX_REPLICATION_TYPE_SETTING.get(settings);
         isRemoteStoreEnabled = settings.getAsBoolean(IndexMetadata.SETTING_REMOTE_STORE_ENABLED, false);
+        isContextAwareEnabled = settings.getAsBoolean(IndexMetadata.SETTING_CONTEXT_AWARE_ENABLED, false);
         isStoreLocalityPartial = settings.get(
             IndexModule.INDEX_STORE_LOCALITY_SETTING.getKey(),
             IndexModule.DataLocalityType.FULL.toString()
@@ -1192,6 +1194,7 @@ public IndexSettings(final IndexMetadata indexMetadata, final Settings nodeSetti
         );
         scopedSettings.addSettingsUpdateConsumer(ALLOW_DERIVED_FIELDS, this::setAllowDerivedField);
         scopedSettings.addSettingsUpdateConsumer(IndexMetadata.INDEX_REMOTE_STORE_ENABLED_SETTING, this::setRemoteStoreEnabled);
+        scopedSettings.addSettingsUpdateConsumer(IndexMetadata.INDEX_CONTEXT_AWARE_ENABLED_SETTING, this::setContextAwareEnabled);
         scopedSettings.addSettingsUpdateConsumer(
             IndexMetadata.INDEX_REMOTE_SEGMENT_STORE_REPOSITORY_SETTING,
             this::setRemoteStoreRepository
@@ -1347,6 +1350,10 @@ public boolean isRemoteStoreEnabled() {
         return isRemoteStoreEnabled;
     }
 
+    public boolean isContextAwareEnabled() {
+        return isContextAwareEnabled;
+    }
+
     public boolean isAssignedOnRemoteNode() {
         return assignedOnRemoteNode;
     }
@@ -2027,6 +2034,10 @@ public void setRemoteStoreEnabled(boolean isRemoteStoreEnabled) {
         this.isRemoteStoreEnabled = isRemoteStoreEnabled;
     }
 
+    public void setContextAwareEnabled(boolean contextAwareEnabled) {
+        isContextAwareEnabled = contextAwareEnabled;
+    }
+
     public void setRemoteStoreRepository(String remoteStoreRepository) {
         this.remoteStoreRepository = remoteStoreRepository;
     }

server/src/main/java/org/opensearch/index/engine/EngineConfig.java

@@ -245,6 +245,7 @@ private static void doValidateCodecSettings(final String codec) {
     private final TranslogConfig translogConfig;
 
     private final TranslogFactory translogFactory;
+    private final boolean isContextAwareEnabled;
 
     /**
      * Creates a new {@link org.opensearch.index.engine.EngineConfig}
@@ -296,6 +297,7 @@ private EngineConfig(Builder builder) {
         this.startedPrimarySupplier = builder.startedPrimarySupplier;
         this.translogFactory = builder.translogFactory;
         this.leafSorter = builder.leafSorter;
+        this.isContextAwareEnabled = builder.isContextAwareEnabled;
     }
 
     /**
@@ -355,6 +357,10 @@ public Engine.Warmer getWarmer() {
         return warmer;
     }
 
+    public boolean isContextAwareEnabled() {
+        return isContextAwareEnabled;
+    }
+
     /**
      * Returns the {@link org.opensearch.index.store.Store} instance that provides access to the
      * {@link org.apache.lucene.store.Directory} used for the engines {@link org.apache.lucene.index.IndexWriter} to write it's index files
@@ -590,6 +596,7 @@ public static class Builder {
         private BooleanSupplier startedPrimarySupplier;
         private TranslogFactory translogFactory = new InternalTranslogFactory();
         Comparator<LeafReader> leafSorter;
+        private boolean isContextAwareEnabled;
 
         public Builder shardId(ShardId shardId) {
             this.shardId = shardId;
@@ -726,6 +733,11 @@ public Builder leafSorter(Comparator<LeafReader> leafSorter) {
             return this;
         }
 
+        public Builder isContextAwareEnabled(boolean isContextAwareEnabled) {
+            this.isContextAwareEnabled = isContextAwareEnabled;
+            return this;
+        }
+
         public EngineConfig build() {
             return new EngineConfig(this);
         }

server/src/main/java/org/opensearch/index/engine/EngineConfigFactory.java

@@ -154,7 +154,8 @@ public EngineConfig newEngineConfig(
         boolean isReadOnlyReplica,
         BooleanSupplier startedPrimarySupplier,
         TranslogFactory translogFactory,
-        Comparator<LeafReader> leafSorter
+        Comparator<LeafReader> leafSorter,
+        boolean isContextAwareEnabled
     ) {
         CodecService codecServiceToUse = codecService;
         if (codecService == null && this.codecServiceFactory != null) {
@@ -188,6 +189,7 @@ public EngineConfig newEngineConfig(
             .startedPrimarySupplier(startedPrimarySupplier)
             .translogFactory(translogFactory)
             .leafSorter(leafSorter)
+            .isContextAwareEnabled(isContextAwareEnabled)
             .build();
     }